Some naval vessels are too large to approach an edge of a body of water in order to enable passengers or crew to board the vessel. Docks extend from the edge of the body of water to the vessel, to allow access to the vessel.
Docks commonly used today consist of boards or blocks that are supported by pilings that are fixed to the bottom of the body of water. Thus, current docks may block sunlight to some sections of the body of water, both during low and high tide. This may prevent the growth of marine life.
The pilings driven into the ground and in constant contact with water. The contact between the water and the pilings may cause the pilings to deteriorate over time. Thus the pilings require treatment against deterioration. If pilings deteriorate, they need to be replaced. Adverse weather conditions may also cause damage to the pilings and/or to the other sections of the docks.
Current docks used in salt water have creosote pilings. If left untreated, creosote pilings deteriorate over time, releasing creosote particles in the water. Creosote is known to be toxic to humans. In fact, according to the Agency for Toxic Substances and Disease Registry (ATSDR), eating food or drinking water contaminated with high levels of coal tar creosote may cause a burning in the mouth and throat, and stomach pains. ATSDR also states that brief direct contact with large amounts of coal tar creosote may result in a rash or severe irritation of the skin, chemical burns of the surfaces of the eyes, convulsions and mental confusion, kidney or liver problems, unconsciousness, and even death. Longer direct skin contact with low levels of creosote mixtures or their vapors can result in increased light sensitivity, damage to the cornea, and skin damage. Longer exposure to creosote vapors can cause irritation of the respiratory tract. The International Agency for Research on Cancer (IARC) has determined that coal tar creosote is probably carcinogenic to humans, based on adequate animal evidence and limited human evidence. The United States Environmental Protection Agency has stated that coal tar creosote is a probable human carcinogen based on both human and animal studies.